Activity of carbon and solubility of carbides in the FCC Fe-Mo-C, Fe-Cr-C, and Fe-V-C alloys
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The activity of carbon in austenitic Fe-Mo-C, Fe-Cr-C, and Fe-V-C alloys has been studied by equilibration with controlled CH4-H2 atmospheres at temperatures in the range 850° to 1200°C. The observations included a number of compositions in the two-phase fields, γ + carbide. Equations are given for the activity coefficient of carbon as a function of temperature and composition in the austenite field and from these the other thermodynamic properties of the solution may be computed as desired. The phase boundaries γ/γ + carbide were determined by breaks in the isoactivity lines. This was supplemented in the case of Fe-Mo-C alloys by metallographic linear analysis of equilibrated samples. The results confirm certain published phase diagrams and discredit others.
KeywordsCarbide Austenite Metallurgical Transaction Phase Boundary Activity Coefficient
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- 4.T. Nishizawa:Thermodynamic Study of Fe-C-Mn, Fe-C-Cr and Fe-C-Mo, Report 4602, Swedish Council for Applied Research, Stockholm, 1967.Google Scholar
- 5.K. Bungardt, E. Schürmann, H. Preisendanz, P. Schüler, and H.-J. Osing:DEW-Tech. Ber., 1969, vol. 9, pp. 439–62.Google Scholar
- 7.R. F. Campbell, S. H. Reynolds, L. W. Ballard, and K. G. Carroll:Trans. TMS-AIME, 1960, vol. 218, pp. 723–32.Google Scholar
- 8.H. Harvig and B. Uhrenius: Report of Materials Center, Royal Institute Tech-nology, TRITA-MAC-0008,1971.Google Scholar
- 9.R. T. Howard and M. Cohen:AIME Trans., 1947, vol. 172, pp. 413–26.Google Scholar
- 11.R. J. Brigham and J. S. Kirkaldy:Trans. TMS-AIME, 1963, vol. 227, p. 538.Google Scholar
- 13.J. Chipman and E. F. Brush:Trans. TMS-AIME, 1968, vol. 242, pp. 35–41.Google Scholar
- 16.R. R. Zupp and D. A. Stevenson:Trans. TMS-AIME, 1966, vol. 236, pp. 1316–23.Google Scholar
- 19.N. A. Savorstyanova and L. A. Shvartsman:Phys. Metals Metallogr., 1969, vol. 9, no. 4, p. 35, English ed.Google Scholar
- 21.W. A. West:Trans. AIME, 1946, vol. 167, pp. 535–49.Google Scholar